DS2781 Maxim Stand-Alone Fuel Gauge battery and w1 slave drivers

Signed-off-by: Renata Sayakhova <rsayakhova@gmail.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

4 files changed, 351 insertions, 0 deletions

diff --git a/drivers/w1/slaves/Kconfig b/drivers/w1/slaves/Kconfig
index d0cb01b42012..eb9e376d6244 100644
--- a/drivers/w1/slaves/Kconfig
+++ b/drivers/w1/slaves/Kconfig
@@ -81,6 +81,19 @@ config W1_SLAVE_DS2780
 
           If you are unsure, say N.
 
+config W1_SLAVE_DS2781
+        tristate "Dallas 2781 battery monitor chip"
+        depends on W1
+        help
+          If you enable this you will have the DS2781 battery monitor
+          chip support.
+
+          The battery monitor chip is used in many batteries/devices
+          as the one who is responsible for charging/discharging/monitoring
+          Li+ batteries.
+
+          If you are unsure, say N.
+
 config W1_SLAVE_BQ27000
         tristate "BQ27000 slave support"
         depends on W1
diff --git a/drivers/w1/slaves/Makefile b/drivers/w1/slaves/Makefile
index 1f31e9fb0b25..c4f1859fb520 100644
--- a/drivers/w1/slaves/Makefile
+++ b/drivers/w1/slaves/Makefile
@@ -10,4 +10,5 @@ obj-$(CONFIG_W1_SLAVE_DS2431)	+= w1_ds2431.o
 obj-$(CONFIG_W1_SLAVE_DS2433)   += w1_ds2433.o
 obj-$(CONFIG_W1_SLAVE_DS2760)   += w1_ds2760.o
 obj-$(CONFIG_W1_SLAVE_DS2780)   += w1_ds2780.o
+obj-$(CONFIG_W1_SLAVE_DS2781)   += w1_ds2781.o
 obj-$(CONFIG_W1_SLAVE_BQ27000)  += w1_bq27000.o
diff --git a/drivers/w1/slaves/w1_ds2781.c b/drivers/w1/slaves/w1_ds2781.c
new file mode 100644
index 000000000000..0d0c7985293f
--- /dev/null
+++ b/drivers/w1/slaves/w1_ds2781.c
@@ -0,0 +1,201 @@
+/*
+ * 1-Wire implementation for the ds2781 chip
+ *
+ * Author: Renata Sayakhova <renata@oktetlabs.ru>
+ *
+ * Based on w1-ds2780 driver
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/types.h>
+#include <linux/platform_device.h>
+#include <linux/mutex.h>
+#include <linux/idr.h>
+
+#include "../w1.h"
+#include "../w1_int.h"
+#include "../w1_family.h"
+#include "w1_ds2781.h"
+
+static int w1_ds2781_do_io(struct device *dev, char *buf, int addr,
+                        size_t count, int io)
+{
+        struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
+
+        if (addr > DS2781_DATA_SIZE || addr < 0)
+                return 0;
+
+        count = min_t(int, count, DS2781_DATA_SIZE - addr);
+
+        if (w1_reset_select_slave(sl) == 0) {
+                if (io) {
+                        w1_write_8(sl->master, W1_DS2781_WRITE_DATA);
+                        w1_write_8(sl->master, addr);
+                        w1_write_block(sl->master, buf, count);
+                } else {
+                        w1_write_8(sl->master, W1_DS2781_READ_DATA);
+                        w1_write_8(sl->master, addr);
+                        count = w1_read_block(sl->master, buf, count);
+                }
+        }
+
+        return count;
+}
+
+int w1_ds2781_io(struct device *dev, char *buf, int addr, size_t count,
+                        int io)
+{
+        struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
+        int ret;
+
+        if (!dev)
+                return -ENODEV;
+
+        mutex_lock(&sl->master->mutex);
+
+        ret = w1_ds2781_do_io(dev, buf, addr, count, io);
+
+        mutex_unlock(&sl->master->mutex);
+
+        return ret;
+}
+EXPORT_SYMBOL(w1_ds2781_io);
+
+int w1_ds2781_io_nolock(struct device *dev, char *buf, int addr, size_t count,
+                        int io)
+{
+        int ret;
+
+        if (!dev)
+                return -ENODEV;
+
+        ret = w1_ds2781_do_io(dev, buf, addr, count, io);
+
+        return ret;
+}
+EXPORT_SYMBOL(w1_ds2781_io_nolock);
+
+int w1_ds2781_eeprom_cmd(struct device *dev, int addr, int cmd)
+{
+        struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
+
+        if (!dev)
+                return -EINVAL;
+
+        mutex_lock(&sl->master->mutex);
+
+        if (w1_reset_select_slave(sl) == 0) {
+                w1_write_8(sl->master, cmd);
+                w1_write_8(sl->master, addr);
+        }
+
+        mutex_unlock(&sl->master->mutex);
+        return 0;
+}
+EXPORT_SYMBOL(w1_ds2781_eeprom_cmd);
+
+static ssize_t w1_ds2781_read_bin(struct file *filp,
+                                  struct kobject *kobj,
+                                  struct bin_attribute *bin_attr,
+                                  char *buf, loff_t off, size_t count)
+{
+        struct device *dev = container_of(kobj, struct device, kobj);
+        return w1_ds2781_io(dev, buf, off, count, 0);
+}
+
+static struct bin_attribute w1_ds2781_bin_attr = {
+        .attr = {
+                .name = "w1_slave",
+                .mode = S_IRUGO,
+        },
+        .size = DS2781_DATA_SIZE,
+        .read = w1_ds2781_read_bin,
+};
+
+static DEFINE_IDA(bat_ida);
+
+static int w1_ds2781_add_slave(struct w1_slave *sl)
+{
+        int ret;
+        int id;
+        struct platform_device *pdev;
+
+        id = ida_simple_get(&bat_ida, 0, 0, GFP_KERNEL);
+        if (id < 0) {
+                ret = id;
+                goto noid;
+        }
+
+        pdev = platform_device_alloc("ds2781-battery", id);
+        if (!pdev) {
+                ret = -ENOMEM;
+                goto pdev_alloc_failed;
+        }
+        pdev->dev.parent = &sl->dev;
+
+        ret = platform_device_add(pdev);
+        if (ret)
+                goto pdev_add_failed;
+
+        ret = sysfs_create_bin_file(&sl->dev.kobj, &w1_ds2781_bin_attr);
+        if (ret)
+                goto bin_attr_failed;
+
+        dev_set_drvdata(&sl->dev, pdev);
+
+        return 0;
+
+bin_attr_failed:
+pdev_add_failed:
+        platform_device_unregister(pdev);
+pdev_alloc_failed:
+        ida_simple_remove(&bat_ida, id);
+noid:
+        return ret;
+}
+
+static void w1_ds2781_remove_slave(struct w1_slave *sl)
+{
+        struct platform_device *pdev = dev_get_drvdata(&sl->dev);
+        int id = pdev->id;
+
+        platform_device_unregister(pdev);
+        ida_simple_remove(&bat_ida, id);
+        sysfs_remove_bin_file(&sl->dev.kobj, &w1_ds2781_bin_attr);
+}
+
+static struct w1_family_ops w1_ds2781_fops = {
+        .add_slave    = w1_ds2781_add_slave,
+        .remove_slave = w1_ds2781_remove_slave,
+};
+
+static struct w1_family w1_ds2781_family = {
+        .fid = W1_FAMILY_DS2781,
+        .fops = &w1_ds2781_fops,
+};
+
+static int __init w1_ds2781_init(void)
+{
+        ida_init(&bat_ida);
+        return w1_register_family(&w1_ds2781_family);
+}
+
+static void __exit w1_ds2781_exit(void)
+{
+        w1_unregister_family(&w1_ds2781_family);
+        ida_destroy(&bat_ida);
+}
+
+module_init(w1_ds2781_init);
+module_exit(w1_ds2781_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Renata Sayakhova <renata@oktetlabs.ru>");
+MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2781 Stand-Alone Fuel Gauge IC");
diff --git a/drivers/w1/slaves/w1_ds2781.h b/drivers/w1/slaves/w1_ds2781.h
new file mode 100644
index 000000000000..82bc66497b43
--- /dev/null
+++ b/drivers/w1/slaves/w1_ds2781.h
@@ -0,0 +1,136 @@
+/*
+ * 1-Wire implementation for the ds2780 chip
+ *
+ * Author: Renata Sayakhova <renata@oktetlabs.ru>
+ *
+ * Based on w1-ds2760 driver
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#ifndef _W1_DS2781_H
+#define _W1_DS2781_H
+
+/* Function commands */
+#define W1_DS2781_READ_DATA             0x69
+#define W1_DS2781_WRITE_DATA            0x6C
+#define W1_DS2781_COPY_DATA             0x48
+#define W1_DS2781_RECALL_DATA           0xB8
+#define W1_DS2781_LOCK                  0x6A
+
+/* Register map */
+/* Register 0x00 Reserved */
+#define DS2781_STATUS                   0x01
+#define DS2781_RAAC_MSB                 0x02
+#define DS2781_RAAC_LSB                 0x03
+#define DS2781_RSAC_MSB                 0x04
+#define DS2781_RSAC_LSB                 0x05
+#define DS2781_RARC                     0x06
+#define DS2781_RSRC                     0x07
+#define DS2781_IAVG_MSB                 0x08
+#define DS2781_IAVG_LSB                 0x09
+#define DS2781_TEMP_MSB                 0x0A
+#define DS2781_TEMP_LSB                 0x0B
+#define DS2781_VOLT_MSB                 0x0C
+#define DS2781_VOLT_LSB                 0x0D
+#define DS2781_CURRENT_MSB              0x0E
+#define DS2781_CURRENT_LSB              0x0F
+#define DS2781_ACR_MSB                  0x10
+#define DS2781_ACR_LSB                  0x11
+#define DS2781_ACRL_MSB                 0x12
+#define DS2781_ACRL_LSB                 0x13
+#define DS2781_AS                       0x14
+#define DS2781_SFR                      0x15
+#define DS2781_FULL_MSB                 0x16
+#define DS2781_FULL_LSB                 0x17
+#define DS2781_AE_MSB                   0x18
+#define DS2781_AE_LSB                   0x19
+#define DS2781_SE_MSB                   0x1A
+#define DS2781_SE_LSB                   0x1B
+/* Register 0x1C - 0x1E Reserved */
+#define DS2781_EEPROM           0x1F
+#define DS2781_EEPROM_BLOCK0_START      0x20
+/* Register 0x20 - 0x2F User EEPROM */
+#define DS2781_EEPROM_BLOCK0_END        0x2F
+/* Register 0x30 - 0x5F Reserved */
+#define DS2781_EEPROM_BLOCK1_START      0x60
+#define DS2781_CONTROL                  0x60
+#define DS2781_AB                       0x61
+#define DS2781_AC_MSB                   0x62
+#define DS2781_AC_LSB                   0x63
+#define DS2781_VCHG                     0x64
+#define DS2781_IMIN                     0x65
+#define DS2781_VAE                      0x66
+#define DS2781_IAE                      0x67
+#define DS2781_AE_40                    0x68
+#define DS2781_RSNSP                    0x69
+#define DS2781_FULL_40_MSB              0x6A
+#define DS2781_FULL_40_LSB              0x6B
+#define DS2781_FULL_4_SLOPE             0x6C
+#define DS2781_FULL_3_SLOPE             0x6D
+#define DS2781_FULL_2_SLOPE             0x6E
+#define DS2781_FULL_1_SLOPE             0x6F
+#define DS2781_AE_4_SLOPE               0x70
+#define DS2781_AE_3_SLOPE               0x71
+#define DS2781_AE_2_SLOPE               0x72
+#define DS2781_AE_1_SLOPE               0x73
+#define DS2781_SE_4_SLOPE               0x74
+#define DS2781_SE_3_SLOPE               0x75
+#define DS2781_SE_2_SLOPE               0x76
+#define DS2781_SE_1_SLOPE               0x77
+#define DS2781_RSGAIN_MSB               0x78
+#define DS2781_RSGAIN_LSB               0x79
+#define DS2781_RSTC                     0x7A
+#define DS2781_COB                      0x7B
+#define DS2781_TBP34                    0x7C
+#define DS2781_TBP23                    0x7D
+#define DS2781_TBP12                    0x7E
+#define DS2781_EEPROM_BLOCK1_END        0x7F
+/* Register 0x7D - 0xFF Reserved */
+
+#define DS2781_FSGAIN_MSB               0xB0
+#define DS2781_FSGAIN_LSB               0xB1
+
+/* Number of valid register addresses */
+#define DS2781_DATA_SIZE                0xB2
+
+/* Status register bits */
+#define DS2781_STATUS_CHGTF             (1 << 7)
+#define DS2781_STATUS_AEF               (1 << 6)
+#define DS2781_STATUS_SEF               (1 << 5)
+#define DS2781_STATUS_LEARNF            (1 << 4)
+/* Bit 3 Reserved */
+#define DS2781_STATUS_UVF               (1 << 2)
+#define DS2781_STATUS_PORF              (1 << 1)
+/* Bit 0 Reserved */
+
+/* Control register bits */
+/* Bit 7 Reserved */
+#define DS2781_CONTROL_NBEN             (1 << 7)
+#define DS2781_CONTROL_UVEN             (1 << 6)
+#define DS2781_CONTROL_PMOD             (1 << 5)
+#define DS2781_CONTROL_RNAOP            (1 << 4)
+#define DS1781_CONTROL_UVTH             (1 << 3)
+/* Bit 0 - 2 Reserved */
+
+/* Special feature register bits */
+/* Bit 1 - 7 Reserved */
+#define DS2781_SFR_PIOSC                (1 << 0)
+
+/* EEPROM register bits */
+#define DS2781_EEPROM_EEC               (1 << 7)
+#define DS2781_EEPROM_LOCK              (1 << 6)
+/* Bit 2 - 6 Reserved */
+#define DS2781_EEPROM_BL1               (1 << 1)
+#define DS2781_EEPROM_BL0               (1 << 0)
+
+extern int w1_ds2781_io(struct device *dev, char *buf, int addr, size_t count,
+                        int io);
+extern int w1_ds2781_io_nolock(struct device *dev, char *buf, int addr,
+                        size_t count, int io);
+extern int w1_ds2781_eeprom_cmd(struct device *dev, int addr, int cmd);
+
+#endif /* !_W1_DS2781_H */